1. Field of the Invention
This invention relates to video processing and particularly to motion compensation of video processes.
2. Background Art
It is a well-known technique in video processing, to identify a motion vector for each pixel and to shift pixels in accordance with those vectors. Such motion compensation is of benefit in myriad video processes, of which standards conversion is a good example. A motion compensated process will be expected to perform considerably better than the equivalent linear process, although at a substantial extra cost in terms of hardware complexity or software processing requirement.
It is further known in simpler arrangements to switch between two processes, one spatial and one temporal, on the basis of whether motion is detected. This has the advantage of avoiding motion smear by switching to spatial processing, but typically suffers from adaption artefacts.
It is an object of one aspect of the present invention to provide a method of taking motion into account, which is less complex and involves less processing than full motion compensation, but which nonetheless offers significant improvements over the equivalent linear process.
There is disclosed in EP O 702 880 a method of reducing the deleterious effects of motion in a video signal process, comprising the steps of conducting the video signal process on a video signal at high bandwidth without motion compensation; conducting a like video signal process without motion compensation at low bandwidth to produce a low bandwidth control signal; conducting a similar video signal process with motion compensation at low bandwidth to produce a low bandwidth motion compensated signal; comparing the control and motion compensated signals to produce an error signal and subtracting the error signal in the high bandwidth video signal process.